Bug 89146 – ntp-4.2.0-r2 + dnsmasq-2.22 breaks round-robin DNS when using pool.ntp.org

• Product: Gentoo Linux
• Status: RESOLVED INVALID

[Description Chris Williams 2005-04-14 19:24:11 UTC]

I'm trying to use the NTP server pool detailed here: http://www.pool.ntp.org/.  

With ntp.conf:
server pool.ntp.org iburst
server pool.ntp.org iburst
server pool.ntp.org iburst
driftfile /var/lib/ntp/ntp.drift
logfile /var/log/ntp.log

I get:
ptolemy root # ntpq -c pe
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 207.245.43.147  .INIT.          16 u    -   64    0    0.000    0.000 4000.00
 207.245.43.147  .INIT.          16 u    -   64    0    0.000    0.000 4000.00
*207.245.43.147  130.126.24.44    3 u    -   64    1  297.719  -15.444  19.102

All the server addresses are equal.  Very ocassionally I will get two different addresses (i.e. one is duplicated).  

My DNS server (current rev of dnsmasq) correctly round-robins the addresses:
ptolemy root # host pool.ntp.org
pool.ntp.org has address 202.55.152.4
pool.ntp.org has address 207.245.43.147
pool.ntp.org has address 216.52.237.152
pool.ntp.org has address 216.165.129.244
pool.ntp.org has address 216.221.118.20
pool.ntp.org has address 217.160.252.229
pool.ntp.org has address 65.175.0.112
pool.ntp.org has address 66.92.250.40
pool.ntp.org has address 66.111.46.200
pool.ntp.org has address 68.148.226.244
pool.ntp.org has address 80.85.129.25
pool.ntp.org has address 130.60.7.52
pool.ntp.org has address 142.179.100.217
pool.ntp.org has address 193.201.200.74
pool.ntp.org has address 194.67.106.186
ptolemy root # host pool.ntp.org
pool.ntp.org has address 194.67.106.186
pool.ntp.org has address 193.201.200.74
pool.ntp.org has address 142.179.100.217
pool.ntp.org has address 130.60.7.52
pool.ntp.org has address 80.85.129.25
pool.ntp.org has address 68.148.226.244
pool.ntp.org has address 66.111.46.200
pool.ntp.org has address 66.92.250.40
pool.ntp.org has address 65.175.0.112
pool.ntp.org has address 217.160.252.229
pool.ntp.org has address 216.221.118.20
pool.ntp.org has address 216.165.129.244
pool.ntp.org has address 216.52.237.152
pool.ntp.org has address 207.245.43.147
pool.ntp.org has address 202.55.152.4


I have reverted to using addresses:
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
driftfile /var/lib/ntp/ntp.drift
logfile /var/log/ntp.log

for 'buggy DNS name resolver' described on the website http://ntp.isc.org/bin/view/Servers/NTPPoolServers.

Reproducible: Always
Steps to Reproduce:
1. install net-misc/ntp and net-dns/dnsmasq
2. configure ntp.conf to use multiple pool.ntp.org servers from rotation
3. start ntpd
4. run ntpq and note that all (or close to all) peers addresses are the same.

Actual Results:  
All (or close to all) peer NTP servers have same address

Expected Results:  
Each NTP server from pool has different address.

pool.ntp.org related 'bugs' also at #54564 and #77657

[Comment 1 Toralf Förster 2005-09-18 08:08:09 UTC]

This also happened without using dnsmasq :-(

[Comment 2 Daniel Black (RETIRED) 2005-12-29 01:43:15 UTC]

I think what your are after is:
ntpd.conf:
servers pool.ntp.org iburst

read man ntpd.conf for details.

specifing the same round robin server multiple time can get same answer.

[Comment 3 Chris Williams 2005-12-29 16:23:51 UTC]

The "servers" option is an OpenNTPD option that is ignored by the currently stable net-misc/ntp-4.2.0.20040617-r3 and, AFAICT, the 4.2.0b development build also.

I notice that the configuration suggested by the www.pool.ntp.org site has changed  to:
driftfile /var/lib/ntp/ntp.drift

server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org

which appears to work for the generic pool, but fails for au.pool.ntp.org.  I'll chase this down on the pool mailing list.

Happy to let this bug drop.